<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>1</title>
</head>
<body>

<h1>Hello girl!</h1>
<button onclick="this.style.display='none'">Click to disappear</button>
<p id="hi"></p>
<script>
    var x=this;
    document.getElementById("hi").innerHTML=x;
    function hi() {
       alert("You submit")
    }
    function f() {
alert("Focus")
    }
</script>
<form action="" onsubmit="hi()">
    name:<input type="text" name="name" >
    age:<input type="date" name="age"  required>
    <input type="submit" value="Click" >
</form>
</body>
</html>